Americans are living longer and many are coping with chronic illnesses that used to result in death. The pain that accompanies these people’s lives is now considered the fifth vital sign, along with blood pressure, temperature, respiratory rate and pulse rate. Chronic pain is the No. 1 cause of adult disability in the United States. It has no predisposition to any group.

About 75 million Americans suffer chronic pain. Of them, 42 percent will experience disability from it and 63 percent will have difficulty with activities of daily living. One out of two people over age 50 will experience chronic pain. The most common types include headaches and low-back pain, although cancers and degenerative diseases, such as arthritis, play major roles and are increasing as life spans increase.